/Engine/Source/Runtime/Core/Public/Containers/SortedMap.h
Returns the value associated with a specified key, or if none exists, adds a value using the default constructor.
A reference to the value associated with the specified key.
[ValueType](API\Runtime\Core\Containers\TSortedMap\ValueType) & FindOrAdd ( const [KeyType](API\Runtime\Core\Containers\TSortedMap\KeyType) & Key )